Since 1943, the University of Rochester has distinguished itself as an internationally recognized center for excellence in research and training in toxicology. This recognition has been achieved in part by the successes of this training grant, which is now in its 34th year of funding. The present renewal application requests funding for 14 pre-doctoral and 4 postdoctoral trainees, to continue a program that is highly interdisciplinary, has a focus on clinical and translational approaches, and a strong emphasis on the basic principles that define the field of toxicology. The overall objective of this broad-based toxicology training program is to provide contemporary pre- and postdoctoral training in the environmental health sciences, such that the graduates are poised to assume significant leadership positions in academia, government, industry and other occupations related to toxicology, environmental health, and public policy. This program is housed within the Department of Environmental Medicine, but its focus is multidisciplinary and interdisciplinary. The 40 training faculty come from a total of 12 different departments within the School of Medicine and Dentistry. As such, this training program takes advantage of the great diversity of specialties and resources available at a major academic medical center by reaching beyond the immediate confines of a single basic science group to draw in exceptional faculty from other basic science and clinical departments. Faculty research programs span the entire spectrum of toxicology, from molecular mechanisms to cellular processes to whole animals and human populations. There are 7 major training areas: Neurotoxicology, Cardiovascular & Pulmonary Toxicology, Osteotoxicology, Molecular Modifiers of Toxicity, Immunotoxicology, Reproductive & Developmental Toxicology, and Stem Cell Toxicology & Epigenetics. This Training Program is distinguished by a long history of outstanding, cutting-edge research and training, the many accomplishments of its former and current students, fellows, and faculty, the remarkable collegiality and extensive research collaborations among its faculty members and trainees, an extensive base of research support, and by a strong institutional commitment to research and training in the environmental health sciences. The program is further enhanced by the presence of an NIEHS Environmental Health Sciences Center and a Division of Occupational Medicine within the Department of Environmental Medicine. Furthermore, the investigators have an NIH Clinical and Translational Sciences Institute, and a highly integrated Biomedical Sciences Graduate structure at the School of Medicine and Dentistry. There are presently 25 toxicology Ph.D. students in residence, with 6 new toxicology Ph.D. trainees starting in July or August, 2012, and 10 postdoctoral fellows currently in training. The overall goal is to educate the next generation of talented environmental health investigators whom are able to generate novel research findings, and then convert these findings into information, resources, or tools that can be used by public health and medical professionals, as well as the public, to improve overall health and well being.